Synthesis of <scp> <scp>K</scp> </scp> ₂ <scp> <scp>SiF</scp> </scp> ₆ : <scp> <scp>Mn</scp> </scp> ⁴⁺ Phosphor from <scp> <scp>SiO</scp> </scp> ₂ Powders via Redox Reaction in <scp>HF</scp> / <scp> <scp>KMnO</scp> </scp> ₄ Solution and Their Application in Warm‐White <scp>LED</scp>

Abstract

In this article, we propose a facile method for synthesis of K 2 SiF 6 : Mn 4+ phosphor and discuss its promising application in warm‐white light emitting diodes ( LED ). The K 2 SiF 6 :Mn 4+ was synthesized from SiO 2 powders through redox reaction in HF / KMnO 4 solution. The optical properties of LED s containing different ratios of K 2 SiF 6 : Mn 4+ phosphor and commercial Ce 3+ ‐doped garnets ( YAG ‐40) yellow–green phosphor were studied. A warm‐white LED , with color temperature of 3510 K and color rendering index of 90.9 and efficacy of 81.56 lm/W was demonstrated.